1. Technical Field
The present invention relates to semiconductor devices and processing, and more particularly to formation methods and structure of a semiconductor device having a metallic source/drain region.
2. Description of the Related Art
Thin channel metal oxide semiconductor field effect transistors (MOSFETs), such as ultrathin body semiconductor-on-insulators (SOI), finFETS, etc., with conventional doped source/drains often suffer from short channel control issues. A Schottky barrier (SB) device with a thin semiconductor body (e.g., thin SOI or finFET) would be an attractive alternative for overcoming the drawbacks of conventional MOSFETs with doped source/drains to provide improved short-channel control. However, fabrication of Schottky barrier devices relies on depositing a metal species (e.g., Ni) and the metal species diffuses and reacts with adjacent semiconductor layers. This is a drawback especially during a formation of silicided source and drain regions. For a thin body SB device, a practical issue is the variation of a silicide layer as a function of the variation of a thin semiconductor layer. This adversely causes device variation (channel length, silicide pipe, etc.).